JP2023012013A - Column-beam connection structure - Google Patents

Abstract

To provide a column-to-beam joint structure in a non-diaphragm type frame having a rigidity equivalent to that of a through-diaphragm type frame or an inner-diaphragm type frame.SOLUTION: A column-to-beam joint structure 10 includes column shafts 11A and 11B, a beam 13, a connection core 12, and a horizontal haunch 31. The connection core 12 is formed such that a relation between a plate thickness tp of the connection core 12 and an outer diameter Bc of the column shafts 11A and 11B is tp≥(Bc/10)+5, and that a relation between an extra length e of an extra length portion 15 of the connection core 12 and the outer diameter Bc of the column shafts 11A and 11B is e≥Bc/4. The horizontal haunch 31 is formed such that a relation between a widthwise length W of the horizontal haunch 31 and a widthwise length W1 of a flat plate portion 12s of the connection core 12 is W≥W1, and that a relation between a length L of the horizontal haunch 31 in the longitudinal direction, the outer diameter Bc of the column shafts 11A and 11B, and a widthwise length W2 of a flange 13a is L≥Bc-W2.SELECTED DRAWING: Figure 2

Description

The present invention is a non-diaphragm type joint which is a column portion made of a square steel pipe, a beam portion made of an H-section steel, and a connecting portion between the column portion and the beam portion made of a square steel pipe. and a column-to-beam joint structure.

Conventionally, this type of column-to-beam joint structure is constructed by welding a plurality of steel pipes, and the welding joints in this case include, for example, a through-diaphragm type, an inner diaphragm type, and the like.
However, the through-diaphragm type, inner-diaphragm type, and other joint types require a large number of assembly man-hours (welding points) and a long welding length, which complicates the overall work. Moreover, according to these joining methods, since the diaphragm provided inside the column cannot be seen from the outside of the column, there is a problem that it is impossible to check whether the diaphragm is appropriately provided inside the column.

Therefore, as a solution to these problems, a non-diaphragm type column and beam that uses a thick short rectangular steel pipe formed by hot forming in the joint that is the connection part between the column and the beam. A joint structure has been provided (for example, Patent Document 1). According to the column-to-beam joint structure employing the thick short rectangular steel pipes obtained by such hot forming, the number of assembly man-hours can be reduced, the welding length can be shortened, and the overall work can be simplified. Also, since the diaphragm is not provided inside the column, it is not necessary to check the diaphragm from the outside of the column.

Japanese Patent Application Laid-Open No. 2003-268877

However, in the beam-to-column joint structure of Patent Document 1, when an external force due to an earthquake or the like is applied to the joint portion, which is the connection portion between the column portion and the beam portion, large stress and strain are concentrated at the joint end portion of the beam portion. . As a result, the joint ends of the beams may be damaged or the joints may be deformed due to the pushing of the beams. In addition, in a non-diaphragm type frame such as the beam-to-column joint structure of Patent Document 1, the deformation of the joint portion is compared to the deformation of the joint portion that occurs in the through-diaphragm type frame or the inner diaphragm type frame. There is the problem of being big. That is, a non-diaphragm type frame such as the beam-to-column joint structure of Patent Document 1 has a problem that its rigidity is smaller than that of a through-diaphragm type frame or an inner-diaphragm type frame.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a beam-to-column joint structure in a non-diaphragm type frame having a rigidity equivalent to that of a through-diaphragm type frame or an inner-diaphragm type frame.

The problems to be solved by the present invention are as described above, and the means for solving the problems will now be described.

That is, the beam-to-column joint structure of the present invention includes a beam made of H-shaped steel having a column made of square steel pipes, a pair of flanges, and a web connecting the flanges, and a beam made of square steel pipes. a non-diaphragm type joint portion that is a connecting portion between the column portion and the beam portion; and a column-to-beam connection structure, wherein the connection portion has a relationship between a plate thickness tp of the connection portion and an outer diameter Bc of the column portion satisfying tp≧(Bc/10)+5. between the extra length e of the excess length formed between the upper end and/or the lower end of the joint portion and the upper end and/or the lower end of the beam portion and the outer diameter Bc of the column portion The relationship is formed so that e≧Bc/4, and the horizontal corbel has a relationship between the widthwise length W of the horizontal corrugation and the widthwise length W1 of the flat plate portion of the joint portion. , W≧W1, and the relationship between the length L of the horizontal corbel and the outer diameter Bc of the column and the width W2 of the flange is such that L≧Bc −W2.

According to the beam-to-column joint structure of the present invention, a horizontal haunch formed under predetermined conditions is provided on one end side of the flange of the beam portion, which is the beam material end of the beam-to-column joint, and further formed under predetermined conditions. Since the non-diaphragm type joints are combined, the rigidity of the frame can be increased, and a non-diaphragm type frame having the same degree of rigidity as the through-diaphragm type frame or the inner diaphragm type frame can be constructed. can be done. Therefore, in the structural design of buildings adopting the non-diaphragm type, the beam ends can be modeled as rigid joints.

It is a partially notched perspective view of the principal part of the column-to-beam joint structure which concerns on this invention. It is a longitudinal front view of the important part of the beam-to-column joint structure according to the present invention. 1 is a cross-sectional plan view of a main part of a beam-to-column joint structure according to the present invention; FIG. It is a partially enlarged cross-sectional plan view of the main part of the beam-to-column joint structure according to the present invention. It is a schematic diagram which shows the analytical model of the beam-column connection structure used for FEM analysis. It is a schematic diagram of the General Yield method used for FEM analysis. It is a figure which shows the result list of FEM analysis.

Hereinafter, embodiments of the present invention will be described based on the drawings. First, the beam-to-column joint structure 10 according to the present invention will be described. In addition, the present invention is not limited to the beam-to-column joint structure 10 described below.

As shown in FIG. 1, the beam-to-column joint structure 10 is arranged between upper and lower column shafts 11A and 11B (an example of a "column") extending in the vertical direction and the upper and lower column shafts 11A and 11B. a joint core 12 (an example of a “joint portion”), a beam 13 (an example of a “beam portion”) provided extending horizontally from each of the four-direction outer surfaces 12c of the joint core 12, The build H-shaped steel 30 provided between the outer surface 12c of the connection core 12 and the end surface of the beam 13 on the one end side.

As shown in FIGS. 1 to 3, the column shafts 11A and 11B are long square steel pipes that are heated by a heating means such as a heating furnace and hot-formed by a forming means such as a forming roll device. The column shafts 11A and 11B have an outer diameter Bc (shaft width) of 200 mm to 550 mm. The plate thickness tc of the column shafts 11A and 11B is 9 mm to 25 mm. The outer radius of curvature of the corner portion 11a of the column shafts 11A, 11B is set to be 2.0 to 3.0 times the plate thickness tc of the column shafts 11A, 11B. The pillar shafts 11A and 11B are formed with a bevel portion having a predetermined angle by cutting the outer portion of the end portion thereof with a processing means such as a cutting device.

The joint core 12 is a short square steel pipe which is heated by heating means such as a heating furnace and hot-formed by forming means such as a forming roll device. As shown in FIGS. 1 to 3, the connection core 12 is a connecting portion between the column shafts 11A and 11B and the beam 13, and is constructed in a non-diaphragm form. A height H1 in the longitudinal direction (vertical direction) of the connection core 12 is set to be longer than a height H2 of the beam 13 (height between the upper and lower flanges 13a). The outer diameter Bp of the joint core 12 is from 220 mm to 575 mm. The plate thickness (panel thickness) tp of the joint core 12 is from 19 mm to 50 mm. Here, the plate thickness (panel thickness) tp of the connection core 12 is determined in relation to the outer diameter (shaft width) Bc of the column shafts 11A and 11B to be joined. ) tp and the outer diameters (shaft widths) Bc of the upper and lower column shafts 11A and 11B are formed so that tp≧(Bc/10)+5. For example, when the outer diameter Bc of the column shafts 11A and 11B is 400 mm, the plate thickness tp of the joint core 12 is set to 45 mm or more. The outer radius of curvature of the corner portion 12 a of the joint core 12 is set to 1.5 to 2.5 times the plate thickness tp of the joint core 12 . Here, the outer radius of curvature of the corner portion 12a of the joint core 12 is defined by the line forming an angle of 45 degrees with the side perpendicular to the adjacent inner and outer surfaces of the joint core 12 and the outer side of the corner portion 12a. is the radius of curvature at the intersection of

As shown in FIGS. 1 and 2, in the beam-to-column joint structure 10, the column shafts 11A and 11B and the joint core 12 are arranged linearly. Specifically, the lower end of the joint core 12 is arranged at the upper end of the lower column shaft 11B, and the upper end of the joint core 12 is arranged at the lower end of the upper column shaft 11A. That is, the connection core 12 is arranged so as to be vertically sandwiched between the column shafts 11A and 11B. The column shafts 11A, 11B and the connection core 12 are joined by welding 17 from the outside. In the beam-to-column joint structure 10, the outer diameter Bp of the connection core 12 is larger than the outer diameter Bc of the column shafts 11A and 11B so that the end faces of the column shafts 11A and 11B can be placed on the end faces of the connection core 12. set long.

As shown in FIGS. 1 to 3, the beam 13 is made of H-beam. The beam 13 is composed of two opposed flat plate-shaped flanges 13a and a web 13b formed between the opposed flanges 13a. The beams 13 are arranged so that the flanges 13a face each other in the vertical direction, and one end sides of the flanges 13a and the webs 13b are welded to the build H-section steel 30 .

The build H-shaped steel 30 is a substantially H-shaped member. One end of the build H-section steel 30 is welded to one end of the beam 13 , and the other end of the build H-section steel 30 is welded to the outer surface 12 c of the joint core 12 . Thereby, the build H-section steel 30 is provided between the outer side surface 12 c of the connection core 12 and one end of the beam 13 to join the connection core 12 and the beam 13 . The build H-section steel 30 is composed of two flat plate-shaped horizontal corbels 31 facing each other and a partition plate 32 formed between the facing horizontal corrugations 31 .

The horizontal haunch 31 is composed of a substantially rectangular plate-like member having the same thickness as the flange 13 a of the beam 13 . One end surface of the horizontal haunch 31 is welded to one end surface of the flange 13a. The other end surface of the horizontal haunch 31 is welded to the outer surface 12c of the joint core 12 . Specifically, the horizontal haunch 31 and the flange 13a are joined by welding 34 while the first backing metal 33 is in contact with one end of the horizontal haunch 31 and one end of the flange 13a. The horizontal haunch 31 and the outer surface 12c of the joint core 12 are joined by welding 36 while the second backing metal 35 is in contact with the other end of the horizontal corbel 31 and the outer surface 12c of the joint core 12. do. By providing the horizontal haunch 31 between the outer surface 12c of the connection core 12 and one end of the beam 13, the stress generated in the connection core 12 is reduced, and the out-of-plane deformation of the steel pipe wall of the connection core 12 is reduced. .

As shown in FIG. 4, the flange width of the horizontal haunch 31 (the length of the portion welded to one end surface of the flange 13a and the outer surface 12c of the connection core 12) W is The width direction length W1 (the length between two R stops R0 at both ends of each side surface of the joint core 12) or more (W≧W1). Specifically, the flange width W of the horizontal corbel 31 is such that when the other end surface of the horizontal corbel 31 is welded to the side surface (flat plate portion 12s) of the connection core 12, both ends of the end surface of the horizontal corbel 31 are , intermediate position R2 (intermediate position between the vertex R1 of the corner portion 12a of the joint core 12 and the R stop R0 of the corner portion 12a including the vertex R1). Here, as shown in FIG. 4, the vertex R1 of the corner portion 12a of the joint core 12 is the position where the outer diameter side surface of the corner portion 12a of the joint core 12 and the diagonal line T of the joint core 12 intersect. Say. Further, the R stop R0 of the corner portion 12a is the position where the curved portion of the corner portion 12a ends on the outer diameter side surface of the corner portion 12a (the position where the flat plate portion 12s on the side surface of the joint core 12 starts. ).

The flange length of the horizontal haunch 31 (the length in the direction perpendicular to the flange width W) L is determined by the outer diameter Bc of the column shafts 11A and 11B and the width of the flange 13a (the length of the portion welded to the horizontal haunch 31). length) W2. Specifically, the horizontal haunch 31 is formed such that the flange length L satisfies L≧Bc−W2. For example, when the outer diameter Bc of the column shafts 11A and 11B is 400 mm and the width W2 of the flange 13a is 200 mm, the flange length L of the horizontal haunch 31 is set to 200 mm or more. In the non-diaphragm type joint core 12, the flange length L of the horizontal haunches 31 provided at the top and bottom of the joint core 12 greatly affects the rigidity and strength of the non-diaphragm type frame.

As shown in FIGS. 1 to 3, the partition plate 32 is composed of a plate-like member having the same thickness as the web 13b of the beam 13. As shown in FIG. One end surface of the partition plate 32 is welded to one end surface of the web 13b. The other end surface of the partition plate 32 is welded to the outer surface 12c of the joint core 12 .

Surplus length of the extra length 15 of the connection core 12 (portion formed between the upper end and/or the lower end of the connection core 12 and the upper end (upper surface) and/or the lower end (lower surface) of the flange 13a of the beam 13) e is set based on the outer diameter Bc of the column shafts 11A and 11B. Specifically, the surplus length portion 15 of the joint core 12 is formed such that the surplus length e satisfies e≧Bc/4. For example, when the outer diameter Bc of the column shafts 11A and 11B is 400 mm, the extra length e of the extra length portion 15 of the joint core 12 is set to 100 mm or more.

As described above, in the beam-to-column joint structure 10, the connection core 12 is configured in a non-diaphragm form. Further, the connection core 12 is formed as a thickened column so that the relationship between the plate thickness tp of the connection core 12 and the outer diameter Bc of the column shafts 11A and 11B is tp≧(Bc/10)+5. ing. Furthermore, the extra length portion 15 of the connection core 12 is adjusted so that the relationship between the extra length e of the extra length portion 15 of the connection core 12 and the outer diameter Bc of the column shafts 11A and 11B satisfies e≧Bc/4. is formed. Further, the beam 13 is constituted by a beam of H-beam including a build H-beam 30 of horizontal haunch 31 at the beam end. Further, the horizontal haunch 31 is formed such that the relationship between the widthwise length W of the horizontal haunch 31 and the widthwise length W1 of the flat plate portion 12s of the joint core 12 satisfies W≧W1. . Furthermore, the horizontal haunch is arranged so that the relationship between the length L in the longitudinal direction of the horizontal haunch 31, the outer diameter Bc of the upper and lower column shafts 11A and 11B, and the width W2 of the flange 13a is L≧Bc−W2. 31 are formed. By constructing the beam-to-column connection structure 10 under the above conditions, the beam-to-column connection structure 10 is a non-diaphragm type frame, and has a column having a rigidity equivalent to that of a through-diaphragm type frame or an inner-diaphragm type frame. A beam joint structure can be constructed.

Next, since the effect of the present invention was confirmed by FEM analysis, this will be described in the following examples.

In the following Examples 1-1 to 1-5A, the column shafts 11A and 11B in the column-to-beam joint structure 10 are composed of □-400×400×19 (R=75) SHC490B hot roll-formed square steel pipes. Then, the beam 13 is H-600 × 300 × 12 × 22, F value 235 N / mm ² or 325 N / mm ² , non-diaphragm type cruciform groove (test body ) was used to perform FEM analysis.

The joint core 12 of the cross-shaped groove in Examples 1-1 and 1-1A was composed of a square steel pipe of □-410×410×40 (R=80) and SHC490C hot forming. In Example 1-1, the plate thickness (panel thickness) tp of the connection core 12 is 40 mm, the extra length e of the extra length portion 15 of the connection core 12 is 100 mm, and the width (beam width) W2 of the flange 13a is 300 mm, and the F value of the beam 13 was set to 235 N/mm ² . In Example 1-1A, the plate thickness tp of the connection core 12 is 40 mm, the extra length e of the extra length portion 15 of the connection core 12 is 100 mm, the width W2 of the flange 13a is 300 mm, and the F value of the beam 13 is 325 N/ ^mm2 . Further, the cross-shaped groove beams 13 in Examples 1-1 and 1-1A were made of H-section steel of SN490B.

The joint core 12 of the cross-shaped groove in Example 1-2 was composed of a square steel pipe of □-410×410×40 (R=80) and SHC490C hot formed. In Example 1-2, the plate thickness tp of the connection core 12 was 40 mm, the extra length e of the extra length portion 15 of the connection core 12 was 50 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N/mm ² . Further, the beams 13 of the cruciform grooves in Example 1-2 were made of SN400B H-section steel.

The joint core 12 of the cross-shaped groove in Example 1-3 was composed of a square steel pipe of □-410×410×36 (R=80) and SHC490C hot forming. In Example 1-3, the plate thickness tp of the connection core 12 was 36 mm, the extra length e of the extra length portion 15 of the connection core 12 was 100 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N/mm ² . Further, the beams 13 of the cruciform grooves in Examples 1-3 were constructed of SN400B H-section steel.

The joint core 12 of the cross-shaped groove in Examples 1-4, 1-5, and 1-5A was composed of a square steel pipe of □-410×410×45 (R=80) and SHC490C hot forming. In Example 1-4, the plate thickness tp of the connection core 12 was 45 mm, the extra length e of the extra length portion 15 of the connection core 12 was 50 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N/mm ² . In Example 1-5, the plate thickness tp of the connection core 12 was 45 mm, the extra length e of the extra length portion 15 of the connection core 12 was 30 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N/mm ² . Further, in Example 1-5A, the plate thickness tp of the connection core 12 is 45 mm, the extra length e of the extra length portion 15 of the connection core 12 is 30 mm, the width W2 of the flange 13a is 300 mm, and the F value of the beam 13 is 325 N/mm ² . Furthermore, the beams 13 of the cruciform grooves in Examples 1-4, 1-5, and 1-5A were constructed of SN490B H-section steel.

Comparative example 1

In Comparative Example 1 for Examples 1-1 to 1-5A, the column shafts 11A and 11B in the beam-to-column joint structure 10 were square steel pipes of □-400×400×19 (R=75) and SHC490B hot roll forming. and the beam 13 is H-600×300×12×22, SN400B H-section steel.

The joint core 12 of the cross-shaped groove in Comparative Example 1 was composed of a square steel pipe of □-400×400×19 (R=75) and SHC490B hot forming. Further, the diaphragm was made of a plate material of SN490C with a plate thickness of 28 mm.

In the following Examples 2-1 to 2-4, the column shafts 11A and 11B in the column-to-beam joint structure 10 are composed of □-400×400×19 (R=75) SHC490B hot roll-formed square steel pipes. Then, the beam 13 is H-600×200×12×22, F value 235N/mm ² or 325N/mm ² , non-diaphragm type cruciform groove (test specimen) composed of H-shaped steel of SN400B is used. FEM analysis was performed.

The joint core 12 of the cross-shaped groove in Examples 2-1 and 2-2 was composed of a square steel pipe of □-410×410×40 (R=80) and SHC490C hot forming. In Example 2-1, the plate thickness tp of the connection core 12 was 40 mm, the extra length e of the extra length portion 15 of the connection core 12 was 100 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N/mm ² . Further, in Example 2-2, the plate thickness tp of the connection core 12 is 40 mm, the extra length e of the extra length portion 15 of the connection core 12 is 150 mm, the width W2 of the flange 13a is 200 mm, and the F value of the beam 13 is 235 N/mm ² .

The joint core 12 of the cross-shaped groove in Examples 2-3 and 2-3A was composed of a square steel pipe of □-410×410×45 (R=80) and SHC490C hot forming. In Example 2-3, the plate thickness tp of the connection core 12 was 45 mm, the extra length e of the extra length portion 15 of the connection core 12 was 100 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N/mm ² . Furthermore, in Example 2-3A, the plate thickness tp of the connection core 12 is 45 mm, the extra length e of the extra length portion 15 of the connection core 12 is 100 mm, the width W2 of the flange 13a is 200 mm, and the F value of the beam 13 is 325 N/mm ² .

The joint core 12 of the cross-shaped groove in Example 2-4 was composed of a square steel pipe of □-410×410×45 (R=80) and SHC490C hot forming. In Example 2-4, the plate thickness tp of the connection core 12 is 45 mm, the extra length e of the extra length portion 15 of the connection core 12 is 50 mm, the width W2 of the flange 13a is 200 mm, and the F value of the beam 13 is 235 N/mm ² .

Comparative example 2

In Comparative Example 2 for Examples 2-1 to 2-4, the column shafts 11A and 11B in the beam-to-column joint structure 10 were square steel pipes of □-400×400×19 (R=75) and SHC490B hot roll forming. and the beam 13 was H-600×200×12×22 and SN400B H-section steel.

The joint core 12 of the cross-shaped groove in Comparative Example 2 was composed of square steel pipe of □-400×400×19 (R=75) and SHC490B hot forming. Further, the diaphragm was made of a plate material of SN490C with a plate thickness of 28 mm.

As shown in FIG. 5, in this example, the test body was modeled with a 1/2 symmetrical model. The connection core 12, column shafts 11A, 11B, and beam 13 from the end to the center of the member are modeled with 8-node solid elements (complete integral elements), and from the center to the tip of the member are modeled by 2-node beam elements (linear material elements). ) was modeled. For the connection of the beam element and the solid element, the beam element end contact point is set as an independent node and the solid element face node is set as a dependent node so that the plane maintenance is established at the connection position. Constraint conditions are that the solid element constrains displacement in the out-of-plane direction on the plane of symmetry (U _z =0), and the beam element constrains out-of-plane displacement, out-of-plane rotation and torsional rotation (U _z = 0, θ _x = 0, θ _y = 0), beam element tips other than the load point are roller-supported so that the material axial direction is free (beam 13: U _y = 0, upper and lower column shafts 11A, 11B : U _x =0). In consideration of the material geometrical nonlinearity, the analysis was an incremental analysis by displacement control at the tip position of the upper column shaft 11A (up to 1/10 rad in interlaminar deformation angle).

The yield strength Qy obtained by FEM load deformation and the total plastic strength Qp obtained by FEM load deformation were calculated by the General Yield method shown in FIG. In addition, sQy in FIG. 7 is the short-term horizontal strength (kN) of the frame determined from the short-term strength of each part, sQp is the total plastic strength (kN) of the frame determined from the short-term strength of each part, and sKj is the joint is the lateral bending rotational stiffness of the core 12 (kN.m/rad), K0 is the initial stiffness (kN/mm) obtained by FEM load deformation, and Ka is the short-term yield strength obtained by FEM load deformation. Secant stiffness (kN/mm) at sQy, and TDK0 is the initial stiffness (kN/mm) of the through-diaphragm type frame with the same beam width.

In this FEM analysis, a non-diaphragm type cruciform test specimen that receives a horizontal load and uses hot-formed square steel pipe (SHC material) for the column shafts 11A and 11B and the connection core 12 is the test object. , the extra length e of the extra length portion 15 of the connection core 12, the width W2 of the flange 13a, and the F value of the beam 13 (beam standard strength Fb) as analysis variables, Examples 1-1 to 1- 5A, Examples 2-1 to 2-4, and Comparative Examples 1 and 2 were subjected to FEM analysis for comparison and examination.

The calculated values sQy and sQp of the horizontal strength of the non-diaphragm type frame shown in FIG. 7 are evaluated on the safe side with respect to the results of the FEM analysis, and there is no problem in operation in structural design. In addition, since the stress at the edge of the flange 13a, which is the end of the beam 13, is prominent, especially when the edge of the flange 13a is applied to the R portion of the joint core 12, a backing metal, an end tab, etc. It is preferable to hold the weld by

In the case of a non-diaphragm type frame, by increasing or decreasing the plate thickness tp of the connection core 12 or the extra length e of the extra length portion 15 of the connection core 12, the horizontal rigidity of the frame is also increased or decreased. The plate thickness tp of the connection core 12 has a greater influence on the rigidity of the frame than the extra length e of the portion 15 . Depending on the plate thickness tc of the column shafts 11A and 11B and the type of steel, the extra length e of the extra length portion 15 of the connection core 12 has a greater effect on the rigidity of the frame than the plate thickness tp of the connection core 12. may become.

In the case of a non-diaphragm type frame, even if the cross-sectional dimensions of the connection core 12 (plate thickness tp of the connection core 12, extra length e of the extra length portion 15 of the connection core 12) are the same, the width W2 of the flange 13a , the out-of-plane bending rotational rigidity (secant line rigidity) Kj of the connection core 12 greatly changes, and the horizontal rigidity of the frame is greatly affected.

The secant stiffness Ka of the non-diaphragm type frame at the time of the short-term horizontal strength sQy is not greatly affected by the material strength of the beam members of the beams 13 (beam reference strength Fb).

Kj by the out-of-plane bending rotational stiffness sKj of the connection core 12 shown in FIG. There are also cases where the As for the evaluation tendency, the case of the beam material standard strength Fb = 235 N/mm ² of the beam steel material in the beam 13 tends to evaluate the rotational rigidity large, and the case of Fb = 325 N/mm ² evaluates the rotational rigidity small. There is a tendency.

In Examples 1-1 to 1-5A and Examples 2-1 to 2-4, the ratio Ka/TDK0 between the secant stiffness Ka of the non-diaphragm type frame and the initial stiffness TDK0 of the through-diaphragm type frame is Excerpt of test specimen dimensions in cases where it exceeds "0.95" and there is no problem in modeling the beam end of the beam 13 to the node as a rigid connection instead of a semi-rigid connection in the modeling of the frame in the structural design of the building. Then, as shown in FIG. 7, seven cases of Examples 1-1, 1-1A, 1-4, 1-5, 1-5A, 2-3, and 2-3A (hatched in FIG. example).

According to these seven examples (Examples 1-1, 1-1A, 1-4, 1-5, 1-5A, 2-3, and 2-3A), the beam end of the beam 13 can be regarded as a rigid joint. The conditions are the following two conditions.
(1) tp≧(Bc/10)+5
tp: plate thickness of the joint core 12 (panel thickness)
Bc: Outer diameter (shaft width) of column shafts 11A and 11B
(2) e≧Bc/4
e: extra length of extra length portion 15 of joint core 12 Bc: outer diameter (shaft width) of column shafts 11A and 11B

Furthermore, by providing the build H-shaped steel 30 having the horizontal haunch 31 at the beam end of the beam 13, the beam end of the beam 13 can be modeled as a rigid joint for structural calculation. Therefore, the column shafts 11A and 11B and the beams 13 are combined in consideration of arranging the build H-shaped steel 30 having the horizontal haunch 31 that satisfies the following two conditions.
(1) W≧W1
W: Flange width of the horizontal haunch 31 (length of the portion welded to one end surface of the flange 13a and the outer surface 12c of the joint core 12)
W1: Width direction length of the flat plate portion 12s of the connection core 12 (length between two R stops R0 at both ends of each side surface of the connection core 12)
(2) L≧Bc−W2
L: Flange length of the horizontal haunch 31 (length in a direction perpendicular to the flange width W)
Bc: Outer diameter (shaft width) of column shafts 11A and 11B
W2: width of the flange 13a (length of the portion welded to the horizontal haunch 31)

As described above, a horizontal haunch 31 formed under predetermined conditions (W≧W1, L≧Bc−W2) is provided on one end side of the flange 13a of the beam 13, which is the beam material end of the beam-column joint, and further , and the non-diaphragm type connection core 12 formed under the predetermined conditions (tp≧(Bc/10)+5, e≧Bc/4), the rigidity of the frame can be increased, and the through-diaphragm type It is possible to configure a non-diaphragm type frame having a rigidity equivalent to that of the inner diaphragm type frame or the inner diaphragm type frame. Therefore, in the structural design of a building adopting the non-diaphragm type, the beam ends of the beams 13 can be modeled as rigid joints.

10 Column beam joint structure 11A Column shaft (column)
11B column shaft (column)
12 Connection core (connection part)
12s flat plate portion 13 beam (beam portion)
13a flange 13b web 31 horizontal haunch

Claims (1)

a pillar made up of square steel pipes;
a beam made of H-section steel having a pair of flanges and a web connecting the flanges;
a non-diaphragm type joint formed by a square steel pipe and serving as a connecting portion between the column portion and the beam portion;
a flat plate-shaped horizontal haunch provided between the end face on one end side of the flange and the side face of the joint;
A column-to-beam connection structure comprising
The joint is
The relationship between the plate thickness tp of the joint portion and the outer diameter Bc of the column portion is formed so that tp≧(Bc/10)+5,
The relationship between the extra length e of the extra length portion formed between the upper end and/or the lower end of the joint portion and the upper end and/or the lower end of the beam portion and the outer diameter Bc of the column portion is e≧ formed to be Bc/4,
The horizontal haunch is
The relationship between the widthwise length W of the horizontal corbel and the widthwise length W1 of the flat plate portion of the joint is formed so that W≧W1,
The relationship between the length L of the horizontal corbel in the length direction, the outer diameter Bc of the column and the length W2 of the flange in the width direction is formed so that L≧Bc−W2. Characteristic column-to-beam joint structure.

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